The present invention generally relates to a conveying device which conveys an object to be conveyed (such as, a substrate), and in particular to a conveying device that is suitable for a vacuum apparatus having a plurality of process chambers (such as, a semiconductor manufacturing apparatus).
In the field of semiconductor manufacturing, a substrate conveying device 101 (such as, shown in FIGS. 14 and 15 has been used heretofore).
The substrate conveying device 101 has a drive section 102, an arm section 103 which is connected to the drive section 102 including a plurality of arms, and an end effector 104 which is connected to the extremity of the arm section 103. The substrate conveying device 101 is configured to support the backside of a substrate W with the top surface of the end effector 104, and transfer the substrate W between a plurality of process chambers (not shown).
The end effector 104 is typically made of ceramics, stainless steel, or the like. If the arm 103 is operated to extend, contract, or rotate at high speed, the end effector 104 also moves at high speed so that there is a problem such that the acceleration on the substrate W makes the substrate W slide over the end effector 104 and the substrate W fails to be conveyed to a proper position.
The conventional technology also has a problem such that the surface of the substrate W can be contaminated with dust generated when the substrate W slides over the end effector 104.
As shown in FIG. 15, it has thus been proposed to provide a plurality of holding sections 105 on the top surface of the end effector 104 so as to make contact with the backside of the substrate W at predetermined points.
The holding sections 105 are typically made of an elastic resin material (such as, rubber and elastomers) and function as antislip pads for suppressing the sliding at the backside of the substrate W. The substrate W can thus be held in a stable conveyance position without sliding over the top surface of the end effector 104 (see, for example, JPA2002-353291).
The holding sections 105 made of an elastic resin material (such as, an elastomer) effectively suppress the sliding of the substrate W when the substrate W and the ambience are relatively low in temperature (for example, 200° C. or lower). If the temperature is high (for example, 300 to 500° C.), however, there is a problem such that the holding sections 105 fail to suppress the sliding of the substrate W due to thermal alteration or deformation.
Even when the temperature is relatively low (for example, 200° C. or lower), the adhesion of the holding sections 105 may sometimes make the substrate W stick to and not properly detachable from the end effector 104. For example, there are problems such that the substrate W sticking to the holding sections 105 may be broken when the substrate W is transferred to a stage in a process chamber, and such that the substrate W cannot be conveyed to a proper position.
Moreover, since the sliding of the substrate W is suppressed in principle by the frictional force between the holding sections 105 and the substrate W, the substrate W slides over the end effector 104 when the substrate W undergoes acceleration beyond the maximum static frictional force which is determined by both the materials. Consequently, there is a problem in that it is impossible to increase the operating speed of the conveying device 101 beyond the maximum static frictional force between the holding sections 105 and the substrate W.